Well packer

ABSTRACT

An improved packer is provided which is adapted to be anchored in a well casing against longitudinal movement in either direction, but which is also retrievable without damage to either the packer or the casing. The packer is equipped with conventional slips and cones located on opposite sides of a conventional elastic packing body. Separate upper and lower mandrel sections are provided with their ends abutting each other adjacent the packing body. The packer is anchored by conventional setting techniques and equipment, and may be retrieved by drawing the upper mandrel away from the lower mandrel. The compressed packing body then relaxes inwardly into the gap separating the ends of the mandrels, thereby releasing backup pressure on the cones. Thereafter, first the upper slip is drawn out of engagement with the casing, and then the lower cones and slip is carried out of engagement with the casing by further upward travel of the upper mandrel.

waited States Patet New York, N.Y.

App]. No. Filed Patented Assignee WELL PACKIER 12 Claims, 4 DrawingFigs.

US. Cl

[52] 166/134, 166/125 Int. Cl E2lb23/06,

E21b 33/ l 29 Field 01 Search 166/134,

[56] References Cited UNITED STATES PATENTS 166/125 166/125 l66/134X166/134 166/134X 3,434,538 3/1969 Kilgore et a].

Primary ExaminerDavid H. Brown Attorneys-Ernest R. Archarnbeau, WilliamJ. Beard,

Stewart F. Moore, David L. Moseley, Edward M. Roney and Wm. R. ShermanABSTRACT: An improved packer is provided which is adapted to be anchoredin a well casing against longitudinal movement in either direction, butwhich is also retrievable without damage to either the packer or thecasing The packer is equipped with conventional slips and cones locatedon opposite sides of a conventional elastic packing body. Separate upperand lower mandrel sections are provided with their ends abutting eachother adjacent the packing body. The packer is anchored by conventionalsetting techniques and equipment, and may be retrieved by drawing theupper mandrel away from the lower mandrel. The compressed packing bodythen relaxes inwardly into the gap separating the ends of the mandrels,thereby releasing backup pressure on the cones. Thereafter, first theupper slip is drawn out of engagement with the casing, and then thelower cones and slip is carried out of engagement with the casing byfurther upward travel of the upper mandrel.

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SHEET 1 OF 2 FIG] ATTORNEYS min-ma m sis-31.921

sum 2 or 2 no.3 F164 David E.Younq INVENIUR BY g I ATTORNEYS WELLIPACKER BACKGROUND OF INVENTION This invention relates to well packersand the like, and more particularly relates to permanently anchoredpackers which are adapted to be retrieved without damage to either thewell or the packer.

There are many instances wherein it is desirable to define and segregateone portion of a borehole from another. In those instances wherein theborehole is lined with a steel casing or the like, this is achieved bysetting a packer assembly in the casing at such depth as may be desired.

In some instances, it may be desired that the well be packed off onlytemporarily, wherein in many other instances it is intended that thepacker be permanently set in the well. So-called temporary packers areusually designed to be wedged in the casing in such manner so to resistmovement in only one direction. This is because retrieval of a temporarypacker is usually achieved by shifting in the opposite direction todisengage it from the interior of the casing or tubing. On the otherhand, permanent packers are wedged in the casing in a manner opposingmovement in either direction. Hence, most permanently anchored packerscannot be dislodged without damage either to the casing or to thepacker.

It is common occurrence for it to become desirable to remove a packerthat has been permanently installed. Since this usually requires adrilling operation and consequent destruction of the packer, this may bequite costly. Moreover, it has become common to construct permanentpackers of drillable materials so that they can be easily shattered bythe drill bit. Although this provides a substantial saving insofar asdrilling time is concerned, it has the disadvantage that a frangible maybe an inherently weaker packer. Furthermore, the fragments and otherdebris from the shattered packer tend to clutter the bottom of theborehole, and may interfere with subsequent operations. In addition, apermanent packer is an expensive piece of equipment as such.

There have been many attempts to provide a packer which is adapted to beanchored immovably in the borehole, but

7 which is also adapted to be retrieved whenever desired without damageto either the packer or the interior of the borehole or casing. However,none of these retrieval permanent packers have met with completeacceptance by the oil and gas industry.

In many cases, the packers have been both anchorable and retrievable,but either special setting techniques or equipment have been required toinstzdl the packer, or else special retrieval techniques and equipmenthave been necessary. In these cases, it has often cost more to retrievesuch a packer than it would have cost to drill through and destroy it.Other packers such as that depicted in US. Pat. No. 3,398,795, have beencapable of being installed and retrieved by special setting and removalequipment, however such equipment and the packer itself are quitecomplicated and expensive.

These and other disadvantages of the prior art are completely overcomewith the present invention, however, and novel packer means is providedherein which may be anchored immovably in a well casing or the like byconventional setting techniques, but which may also be adapted to beselectively retrieved by conventional retrieval techniques and equipmentwithout damage to either the packer assembly or the casing.

THE INVENTION In a preferred embodiment of the invention, an improvedpacker assembly is provided which is equipped with a conventionalelastic packing body located intermcdiately of a generally conventionalassembly of upper and lower slips and cones. Thus, the packer assemblymay be anchored permanently in the well casing against longitudinalmovement in either direction in the borehole.

An essential difference in the subject packing assembly is that themandrel has separate upper and lower sections with abutting ends.Further, the elastic packing element or body is preferably positionedadjacent the butting ends of the two mandrel sections, when the packingassembly is installed or set in the well.

In the preferred embodiment of the invention, the upper cone isreleasably secured to the upper mandrel section, and the lower cone isadvanced toward the upper cone to compress the elastic packing body.This, in turn, squeezes the packing body circumferentially outward ofthe packing assembly and into fluidtight engagement with the insidecircumference of the casing (as well as circumferentially inward againstthe exterior surfaces of the abutting ends of the two mandrel sections).The upper and lower slips are shifted into engagement with the insidesurface of the casing in a conventional manner.

In retrieving the packer assembly, the upper mandrel is initiallyengaged by a retrieving tool and an upward pull is used to release theconnection between the upper cone and mandrel section. The upper mandrelsection is then raised a limited distance through the borehole from andindependently of the lower mandrel section and the other components ofthe packer assembly. The compressed packing body will thereupon expandinwardly into the gap established by the separated ends of the mandrelsections, and as the packing element expands into this widening gap,this in turn releases or reduces the longitudinal back pressure againstthe cones.

After the upper mandrel section has been raised a substantial portion ofthe maximum distance it can travel from the lower mandrel section, itengages the upper slip carrier and carries it upward from the upper slipor slips. The upper slip carrier is preferably loosely interlinked withthe upper slips by some conventional means such as by a dovetail orl-connection. Thus, upward movement of the upper slip carrier will carrythe upper slips away from between the casing and the canted outersurface of the upper cone or cones. Since back pressure has previouslybeen removed or released from the upper cone, the upper slips are nolonger jammed or wedged between the upper cone and the inside surface ofthe casing. Thus, the upper slips are easily pulled from between thecasing and the upper cone without the slightest damage to the insidesurface of the casing.

Like the upper slips, cone, and slip carrier, the lower slips, cone, andcarrier are also slidably mounted on the exterior surface of the lowermandrel section, and are also linked together in tandem by dovetail orT-connections or the like. Also, the lower cone is relieved of backpressure by relaxation of the elastic packing body, the same as with theupper cone. Thus, when the upper mandrel section is raised the fulldistance from the lower mandrel section, the lower mandrel section isengaged by the retrieval tool. Thereafter, further upward movement ofthe upper mandrel section will be accompanied by corresponding upwardmovement of the lower mandrel section.

As the lower mandrel section is carried up the casing, it first engagesthe lower cone and carries it up through the borehole. Thereafier, thelower cone engages and carries up the lower slips which have beendisengaged from the casing wall by relaxation of the packing bodyfollowed by upward movement of the lower cone away from the lower slips.Finally, the lower slips engage and carry the lower slip carrier up theborehole.

Accordingly, it is an object of the present invention to provide animproved packing assembly which is adapted to be immovably anchored in acasing or the like, and which is also retrievable without damage to orloss of any portion of the assembly and without damage to the casing.

It is further an object of the present invention to provide an improvedpacking assembly which is adapted to be immovably or permanentlyanchored in a casing by conventional setting techniques, and which isalso adapted to be retrieved by conventional retrieval techniques andequipment without damage to or loss of any portion of the packingassembly and without damage to the casing.

It is a specific object of the present invention to provide an improvedpacking assembly having upper and lower slips and cones separated by anelastic packing body and mounted on a pair of abutting mandrels whichare separable to permit relaxation of the packing body and release ofthe cones and slips for retrieval from a well casing or the like.

These and other objects and features of the present invention willbecome apparent from the following detailed description, whereinreference is made to the figures in the accompanying drawings.

IN THE DRAWINGS FIG. I is a pictorial representation, partly in crosssection, of a packing assembly embodying one form of the presentinvention, wherein the packing assembly is depicted in a relaxedcondition prior to being anchored in a casing.

FIG. 2 is pictorial representation, also partly in cross section, of theapparatus depicted in FIG. 1, wherein the packing assembly is depictedin a set condition after being anchored against longitudinal movement ineither direction through the casing.

FIG. 3 is a pictorial representation, also partly in cross section, ofthe apparatus depicted in FIGS. I and 2, and illustrating release of theupper slips from the casing during retrieval of the packer assembly fromthe casing.

FIG. 4 is a pictorial representation, partly in cross section, of theapparatus depicted in FIGS. 1-3, and illustrating release of the lowerslips from the casing during retrieval of the packer assembly from thecasing.

DETAILED DESCRIPTION Referring now to FIG. 1, there may be seen apictorial representation, partly in cross section, of an improvedpacking assembly such as a production packer embodying an exemplary fonnof the present invention. In particular, there is depicted a simplifiedrepresentation of a steel well casing 2 or the like, containing apacking assembly composed of an upper mandrel section 8 and a lowermandrel section 10 slidably disposed about the exterior surface of aportion of conventional setting equipment which will hereinafter bedescribed. As may further be seen, the upper and lower mandrel sections8 and 10 are arranged in abutting end-to-end relationship one to theother, with an annular elastic packing body 18 disposed about theabutting ends of these two components.

As may further be seen in FIG. 1, the upper end of the upper mandrelsection 8 is preferably provided with inside ratchet threads 9 and anannular exterior shoulder 24. An upper slip carrier 20 of generallyconventional configuration, but with an inside upper shoulder portion21, is slidably positioned about the upper end of the upper mandrelsection 8, and preferably fixedly attached thereto by means of a shearpin 36 or other frangible link of conventional design. In addition tothe upper annular shoulder 21, the upper slip carrier 20 may further beseen to preferably include a lower annular shoulder 22, with an annularspace 23 therebetween for accommodating longitudinal movement of theexterior annular shoulder 24 of the upper mandrel section 8.

An upper cone or expander 16 of conventional configuration is preferablyslidably mounted about the upper mandrel section 8, and in abuttingengagement with the upper edge of the packing body 18. A shear ring 40,or other frangible linking device of suitable design, is provided fortemporarily fixedly securing the upper cone 16 to the exterior surfaceof the upper mandrel section 8. Upper slips [4 of conventional designmay be slidably positioned about the upper mandrel section 8, betweenthe upper slip carrier 20 and the canted surface of the upper cone l6,and may be temporarily secured to the upper cone 16 by means of shearpins 37 or the like. In addition, the upper end of the upper slips 14are preferably linked loosely to the upper slip carrier 20 by means of aT-connection 25, or the like, and the lower end of the upper slips 14may be'loosely linked to the upper expander 16 by means ofa dovetailconnection or the like.

As may further be seen in FIG. 1, the lower mandrel section 10 mayinclude a series of exterior threads or grooves 13 adjacent its upperend for fixedly positioning the packing body 18 relative to the othercomponents in the depicted packing assembly and may further include aninside annular latching groove II adjacent its lower end, for reasonswhich will hereinafter be explained. Further, the lower mandrel section10 preferably includes an exterior shoulder 12 located generallyintennediately of the upper and lower ends of the lower mandrel section10.

As depicted, a lower slip carrier 26 is preferably slidably mounted onthe lower end of the lower mandrel section 10, and temporarily fixedthereto by means of a shear pin 39, or the like. The lower slip carrier26 preferably includes an inside annular latching groove 27 for engagingthe lower end of the setting tool. A lower expander 17 of conventionaldesign is preferably positioned in abutting engagement with the lowersurface of the packing body 18, and lower slips 15 of conventionaldesign are preferably positioned between the upper end of the lower slipcarrier 26, and the canted lower surface of the expander 17. Shear pins38 or the like may be provided for temporarily securing the lower slipsl5 and expander 17 together, and the lower slips 15 are preferablyloosely linked to the lower slip carrier 26 by means of a T-connection29 or other suitable means. In addition, the lower slips and cones maybe loosely linked together by means of a dovetail connection or thelike.

As may be seen, the packing assembly depicted in FIG. I is representedas being in a relaxed condition prior to being anchored in the casing 2.In setting the packing assembly, conventional setting equipment may beused such as the cylindrical tension member or mandrel 3 having asetting sleeve 4 slidably disposed about its circumference and anchoredat the upper end by means of a shear pin 5. The lower end of the settingsleeve 4 may be seen to include a plurality of collet fm gets 6 whichare each provided with outwardly directed or extended tips 7 forengaging the groove 27 in the lower end of the lower slip carrier 26.The setting tool mandrel 3 may further include an annular collar 30mounted on its exterior at a preselected location immediately below theshear pin 5. The setting tool will further be seen to include a suitablecompressional member 32 (not depicted in FIG. I, see FIG. 2).

During the setting operation, the setting tool mandrel 3 and sleeve 4are positioned substantially as illustrated in FIG. I, with the tips 7of the collet fingers 6 engaging the groove 27 of the lower slip carrier26 to prevent downward movement of the packingassembly. The mandrel 3and sleeve 4 are raised through the casing 2, while the compressionalmember 32 is urged downwardly against the upper end of the upper slipcarrier 20, thereby urging the upper slip carrier 20 downwardly againstthe upper slips l4, and the lower slip carrier 26 upwardly against thelower slips 15. When sufficient force has been applied in this manner,shear pins 37 and 38 will be sheared, and the upper and lower slipcarriers 20 and 26 will be urged toward each other along the exteriorsurfaces of the upper and lower mandrel sections 8 and 10, respectively.This will urge the upper and lower slips I4 and 15 together against theupper and lower cones l6 and 17, respectively, thus shifting themoutwardly into gripping engagement with the casing. Since the upper cone16 is fixed to the mandrel section 8, the lower cone 17 will be advancedtoward the upper cone to compress the packing element 18. Thus thepacking element 18 will be squeezed outwardly against the inside surfaceof the casing 2. In this respect, it is convenient to provide thepacking element 18 with antiextrusion springs 19 to restrict deformationof the packing element 18 to the direction of the casing 2.

When the packing element 18 has been squeezed sufficiently against thecasing 2 and the upper and lower slips I4 and I5 firmly set in lockingengagement with the inside surface of the casing 2, further tensionforce on the setting tool mandrel 3 will cause the shear pin 5 to sever,and the setting tool mandrel 3 to slide upwardly within the setting toolsleeve 4 until the tips 7 of the collet fingers 6 are disengaged fromthe groove 27 in the lower slip carrier 26, whereupon the collar 39 willengage the upper end of the setting sleeve 1 at the shoulder 31 andcarry the setting tool sleeve 4 out of the upper and lower mandrelsections 8 and 10. The packing assembly depicted in FIGS. 1 and 2 willthen be completely installed in the casing 2, and anchored againstlongitudinal movement in either direction.

Referring now to FIGS. 3 and 4, there may be seen a pictorialrepresentation of the apparatus depicted in FIGS. 1 and 2, and moreparticularly depicting the arrangement of various parts during retrievalof the packing assembly after it has been fully anchored as illustratedin FIG. 2. In particular, a retrieval tool 33 having provision forengaging the ratchet threads 9 at the upper end of the upper mandrelsection 8, is slidably inserted within the upper and lower mandrelsections 8 and until its collet fingers 34 and gripping tips 35 extendbelow the lower end of the lower mandrel section 10. When the retrievaltool 33 is raised through the casing 2, the pin 40 is sheared and theupper mandrel section 8 initially moves upwardly from the lower mandrelsection 10 and independently of the other components of the depictedpacking assembly. As may also be seen, lifting the upper mandrel section8 creates a gap between the abutting ends of the mandrel sections 8 and10, and the compressed packing element 18 accordingly relaxes laterallyinto this gap in the manner illustrated in FIG. 3. Expansion into thegap results in relaxation of the packing element 18, and this, in turn,removes the force which holds the upper and lower cones l6 and 17 apart.Thus, lifting the upper mandrel section 8 away from the lower mandrelsection 10 releases the upper and lower cones l6 and 17 which are wedgedunder the upper and lower cones 16 slips 14 and 15, respectively, andthis efi'ectively releases the slips 14 and 15. After the packingelement 18 is fully relaxed, however, it will revert to its normalconfiguration as illustrated in FIG. 4.

Further, upward travel of the retrieval tool 33 carries the uppermandrel section 8 upward through the casing 22, and independently of theupper cone 16, slips l4, and slip carrier 20, until the shoulder 24engages the upper slip carrier 20 at the upper inside annular shoulder21. Thereupon, upward movement of the upper mandrel section 8 will carrythe upper slip carrier 20 with it. Since the upper slip carrier 20 islinked to the upper slips 14 by means of the T-connection 25, this will,in turn, carry the upper slips 14 out of engagement with the insidesurface of the casing 2.

As may be seen, there is no direct link between the upper and lowermandrel sections 8 and 10. However, when the retrieval tool 33 is moveda sufficient distance upwardly through the casing 2, the latching tips35 of the collet fingers 34 of the retrieval tool 33 will engage theannular groove 11 inside the lower mandrel section 10, and thereafterupward travel of the retrieval tool 33 will also carry the lower mandrelsection 10 with it through the casing 2.

As the lower mandrel section 10 is carried upwardly through the casing2, it will move independently of the lower cone l7, slips 15, and slipcarrier 26, until the shoulder portion 12 of the lower mandrel section10 engages the lower cone 17 as depicted in FIG, 3. Thereafter, furtherupward movement of the lower mandrel section 10 will carry the lowercone 17 with it and out from under the lower slips 15. This, in turn,disengages the lower slips 15 from the inside surface of the casing 2,and since the lower cone l7 and slips 15 are preferably interconnectedby means of a dovetail connection, or the like, upward movement of thelower cone 17 by the lower mandrel section 10, will carry the lowerslips 15 with it. Further, the lower slips 15 are linked to the lowerslip canier 26 by means of a ward movement of the lower slips 15 willcarry the lower slip carrier 26 upwardly through the casing 2.

Referring to FIG. 3, there may be seen a pictorial illustration of theapparatus wherein the upper slips 14 have been disengaged from theinside of the casing 2 by upward movement of the retrieval tool 13, butwherein the lower slips 15 are still locked to the inside surface of thecasing 2. Referring to FIG. 4, there may be seen an illustration of thegeneral configuration of the apparatus depicted in FIGS. l-3, whereinboth the upper and lower slips l4 and have been disengaged from theinside of the casing 2, but wherein all of the components of thedepicted packing assembly are linked together to be fully recovered fromthe well without loss of or damage to any of the components of thedepicted packing assembly.

The upper and lower slips l4 and 15 and cones l6 and 17 may be of anyconventional configuration, except as hereinbefore specifically noted.The shear device 40 prevents inadvertent release of the packer due totension force producted, for example, by the effects of temperaturechanges on a production stinger that is latched to the threads 9 duringproduction operations.

It will be apparent from the foregoing that many other variations andmodifications may be made in the structures and methods described hereinwithout substantially departing from the essential concept of thepresent invention. Accordingly, it should be clearly understood that theforms of the invention described herein and depicted in the accompanyingdrawings, are exemplary only and are not intended as limitations in thescope of the present invention.

What is claimed is:

1. A well packer apparatus comprising:

a body member including upper and lower sections having abutting endportions;

an upper expander means and a lower expander means on said body member;

packing means on said body member and surrounding said abutting endportions and adapted to be compressed and expanded into sealing contactwith a well casing by advancement of one of said expander means towardthe other of said expander means;

upper and lower slip means cooperable respectively with said upper andlower expander means and adapted to be shifted outwardly thereby intogripping contact with the well casing; and

releasable means for attaching the other of said expander means to oneof said sections, release of said releasable means enabling separationof said sections and release of the compression in said packing means.

2. The apparatus described in claim 1 wherein said releasable meansincludes a shearable member between said one expander means and said onebody member section, said shearable means shearing only in response to apredetermined longitudinal force applied to said one body membersection.

3. The apparatus described in claim 2, wherein said upper expander meansis adapted for slidable movement relative to said upper section of saidbody member, said releasable means attaching said upper section to saidupper expander means.

4. The apparatus described in claim 3, wherein said shearable member isadapted to shear in response to said predetermined longitudinal forceupwardly applied to said upper section of said body member.

5. The apparatus described in claim 4, wherein said upper section ofsaid body member includes means for moving said upper slip means fromgripping contact with said well casing and thereby releasing said upperexpander means from compressive engagement with said packing means.

6. A well packer apparatus comprising an upper mandrel section adaptedto be longitudinally disposed in a well casing or the like,

a lower mandrel section also adapted to be longitudinally disposed insaid well casing and disposed in abutting endto-end relationship withsaid upper mandrel section,

a resilient annular packing body disposed about said abutting ends ofsaid mandrel sections and compressible into fluidtight engagement withsaid well casing,

upper expander means slidably mounted on and releasably secured to saidupper mandrel section,

upper slip means slidably mounted on said upper mandrel section fordownward wedged engagement between said upper expander means and saidwell casing,

lower expander means slidably mounted on said lower mandrel section, and

lower slip means slidably mounted on said lower mandrel section forurging said lower expander upwardly against said packing body tocompress said packing body between said upper and lower expander meansand further adapted for upward wedged engagement between said lowerexpander means and w'd well casing,

shear means for releasably coupling said upper expander means to saidupper mandrel section, said shear means being releasable upon theapplication of sufiicient force to said upper mandrel section for movingsaid upper mandrel section relative to said lower mandrel section.

7. The apparatus described in claim 6 and including means on said uppermandrel section for moving said upper slip means out of wedgedengagement between said well casing and said upper expander means aftersaid shear means is operated to release said upper expander means fromsaid upper mandrel section.

8. The apparatus described in claim 7, wherein said compressed packingbody is located on said mandrel sections so as to expand into the spacebetween the separated abutting ends of said mandrel sections upon upwardmovement of said upper mandrel section to reduce setting pressure onsaid upper slip means and enable release of said upper slip and expandermeans.

9. The apparatus described in claim 8, wherein said packing body isslidably connected to said upper mandrel section and fixedly connectedto said lower mandrel section.

10. A well packer for use in a well bore comprising longitudinallyextending body means which are normally functionally integral forsetting of a well packer and are selectively separable for release of awell packer, packing means on said body means for sealing with respectto the wall of a well bore, said body means providing internal supportfor said packing means and being separable into spaced-apart sections torelease such support,

anchor means on said body means above and below said packing means, saidanchor means being movable relative to one another for compressing saidpacking means therebetween and for gripping engagement with the wall ofa well bore to prevent release of compressive forces in a compressedpacking means, and

means for selectively effecting a separation of said body meanssupporting said packing means to release compressive forces in saidpacking means subsequent to compression of said packing means andgripping of the wall of a well bore by said anchor means.

11. A well packer for use in a 'well bore and including longitudinallyextending body means which are functionally integral during setting andsealing of said well packer and longitudinally separable for release ofsaid well packer,

packing means on said body means for sealing with respect to a wellbore,

anchor means on said body means above and below said packing means, saidanchor means having expanders and slips and being movably mounted forrelative movement toward one another to compress said packing means toseal with respect to a well bore and for anchoring to a well boreagainst movement in either direction in response to the compressionforces in an expanded packing means, and

means for selectively effecting a separation of said body means aftersaid packing means are compressed, said body means being separable in alocation permitting release of the compression forces in a compressedpacking means.

12. A well packer for use in a well bore comprising longitudinallyextending body means which are functionally integral during setting andsealing of a well packer and are longitudinally separable into upper andlower sections for release of such well packer,

packing means on said body means for sealing with respect to a wellbore, said packing means extending over said ugper and lower sectionsanc or means on said body means above and below said packing means, saidanchor means being relatively movable between an inactive position andan active position compressing the packing means into sealing engagementwith the wall of a well bore, said anchor means including slips movablebetween an inactive position and an active position engaging the wall ofa bore well bore,

first means releasably retaining said anchor means and slips in aninactive position, said first means being releasable in response toopposing forces applied to said anchor means to permit compression ofsaid packing means into sealing engagement with the wall of a well boreand engagement of said slips with the wall of a well bore,

second means releasably retaining one of said anchor means fixedrelative'to said body means during sealing of a well packer andengagement of said slips, said second means being independentlyreleasable to permit movement of one of said body sections relative tosaid one anchor means to separate said upper and lower sections andpermit relaxation of the compressive forces in said packing means, and

means on said upper and lower sections for moving said slips to aninactive position in response to longitudinal movement of said separatedbody sections relative to said anchor means.

1. A well packer apparatus comprising: a body member including upper andlower sections having abutting end portions; an upper expander means anda lower expander means on said body member; packing means on said bodymember and surrounding said abutting end portions and adapted to becompressed and expanded into sealing contact with a well casing byadvancement of one of said expander means toward the other of saidexpander means; upper and lower slip means cooperable respectively withsaid upper and lower expander means and adapted to be shifted outwardlythereby into gripping contact with the well casing; and releasable meansfor attaching the other of said expander means to one of said sections,release of said releasable means enabling separation of said sectionsand release of the compression in said packing means.
 2. The apparatusdescribed in claim 1 wherein said releasable means includes a shearablemember between said one expander means and said one body member section,said shearable means shearing only in response to a predeterminedlongitudinal force applied to said one body member section.
 3. Theapparatus described in claim 2, wherein said upper expander means isadapted for slidable movement relative to said upper section of saidbody member, said releasable means attaching said upper section to saidupper expander means.
 4. The apparatus described in claim 3, whereinsaid shearable member is adapted to shear in response to saidpredetermined longitudinal force upwardly applied to said upper sectionof said body member.
 5. The apparatus described in claim 4, wherein saidupper section of said body member includes means for moving said upperslip means from gripping contact with said well casing and therebyreleasing said upper expander means from compressive engagement withsaid packing means.
 6. A well packer apparatus comprising an uppermandrel section adapted to be longitudinally disposed in a well casingor the like, a lower mandrel section also adapted to be longitudinallydisposed in said well casing and disposed in abutting end-to-endrelationship with said upper mandrel section, a resilient annularpacking body disposed about said abutting ends of said mandrel sectionsand compressible into fluidtight engagement with said well casing, upperexpander means slidably mounted on and releasably secured to said uppermandrel section, upper slip means slidably mounted on said upper mandrelsection for downward wedged engagement between said upper expander meansand said well casing, lower expander means slidably mounted on saidlower mandrel section, and lower slip means slidably mounted on saidlower mandrel section for urging said lower expander upwardly againstsaid packing body to compress said packing body between said upper andlower expander means and further adapted for upward wedged engagementbetween said lower expander means and said well casing, shear means forreleasably coupling said upper expander means to said upper mandrelsection, said shear means being releasable upon the application ofsufficient force to said upper mandrel section for moving said uppermandrel section relative to said lower mandrel section.
 7. The apparatusdescribed in claim 6 and including means on said upper mandrel sectionfor moving said upper slip means out of wedged engagement between saidwell casing and said upper expander means after said shear means isoperated to release said upper expander means from said upper mandrelsection.
 8. The apparatus described in claim 7, wherein said compressedpacking body is located on said mandrel sections so as to expand intothe space between the separated abutting ends of said mandrel sectionsupon upward movement of said upper mandrel section to reduce settingpressure on said upper slip means and enable release of said upper slipand expander means.
 9. The apparatus described in claim 8, wherein saidpacking body is slidably connected to said upper mandrel section andfixedly connected to said lower mandrel section.
 10. A well packer foruse in a well bore comprising longitudinally extending body means whichare normally functionally integral for setting of a well packer and areselectively separable for release of a well packer, packing means onsaid body means for sealing with respect to the wall of a well bore,said body means providing internal support for said packing means andbeing separable into spaced-apart sections to release such support,anchor means on said body means above and below said packing means, saidanchor means being movable relative to one another for compressing saidpacking means therebetween and for gripping engagement with the wall ofa well bore to prevent release of compressive forces in a compressedpacking means, and means for selectively effecting a separation of saidbody means supporting said packing means to release compressive forcesin said packing means subsequent to compression of said packing meansand gripping of the wall of a well bore by said anchor means.
 11. A wellpacker for use in a well bore and including longitudinally extendingbody means which are functionally integral during setting and sealing ofsaid well packer and longitudinally separable for release of said wellpacker, packing means on said body means for sealing with respect to awell bore, anchor means on said body means above and below said packingmeans, said anchor means having expanders and slips and being movablymounted for relative movement toward one another to compress saidpacking means to seal with respect to a well bore and for anchoring to awell bore against movement in either direction in response to thecompression forces in an expanded packing means, and means forselectively effecting a separation of said body means after said packingmeans are compressed, said body means being separable in a locationpermitting release of the compression forces in a compressed packingmeans.
 12. A well packer for use in a well bore comprisinglongitudinally extending body means which are functionally integralduring setting and sealing of a well packer and are longitudinallyseparable into upper and lower sections for release of such well packer,packing means on said body means for sealing with respect to a wellbore, said packing means extending over said upper and lower sections,anchor means on said body means above and below said packing means, saidanchor means being relatively movable between an inactive position andan active position compressing the packing means into sealing engagementwith the wall of a well bore, said anchor means including slips movablebetween an inactive position and an active position engaging the wall ofa bore well bore, first means releasably retaining said anchor means andslips in an inactive position, said first means being releasable inresponse to opposing forces applied to said anchor means to permitcompression of said packing means into sealing engagement with the wallof a well bore and engagement of said slips with the wall of a wellbore, second means releasably retaining one of said anchor means fixedrelative to said body means during sealing of a well packer andengagement of said slips, said second means being independentlyreleasable to permit movement of one of said body sections relative tosaid one anchor means to separate said upper and lower sections andpermit relaxation of the compressive forces in said packing means, andmeans on said upper and lower sections for moving said slips to aninactive position in response to longitudinal movement of said separatedbody sections relative to said anchor means.